[austinz]

Because each set of numbers measures a different set of things. Singapore and Luxembourg may have a larger per capita GDP than the U.S. or China, but the absolute size of their economies is far too small to allow them similar amounts of military or diplomatic influence compared to the larger countries. Likewise, a small country where everyone earns a lot of money is more attractive a market for a company selling luxury goods than a country where the total GDP is thinly spread across a large but destitute population.